The present invention relates generally to hot air sterilization devices, and more particularly provides a device which utilizes recirculating, high velocity hot impingement air to sterilize medical and dental instruments or the like, and is provided with an improved internal insulation structure together with a variety of other structural improvements.
The sterilizer disclosed and described in my commonly assigned copending U.S. application Ser. No. 044,909, which is incorporated herein by reference, has proven to be quite effective in rapidly, inexpensively and non-corrosively sterilizing and depyrogenating metal dental and surgical instruments. As described in such copending application, the sterilization of the instruments is achieved utilizing a recirculating flow of high velocity, hot air impingement jets within a sterilization chamber formed in an inner housing portion of the sterilizer. This inner housing is disposed within an outer housing which forms with the inner housing an insulation space in which sheets of suitable fibrous insulating material are disposed. Suitable cooling fan means (not shown) were used to circulate cooling air around this insulation space within the outer housing.
The hot sterilizing air is recirculated within the sterilization chamber by means of an air circulating fan disposed within the outer housing and having an inlet communicating with the sterilization chamber. Air discharged from the fan is forced into a supply plenum formed in the inner housing beneath the sterilization chamber. The recirculating air is heated by means of an electric heating element disposed in the supply plenum.
In the course of developing this particular sterilizer, it has been found that this insulation, air delivery and heating structure creates certain maintenance disadvantages. For example, when it becomes necessary to remove or repair the recirculating air fan disposed within the outer housing, exposed portions of the fibrous insulation sheets are often damaged, causing small pieces thereof to be dislodged and fall into the interior of the outer housing. Additionally, to repair or replace the electric air heating element, it was necessary to provide access to the interior of the supply plenum disposed within the inner housing. Further, cooling air flow within the outer housing often entrained dislodged bits of fibrous insulation causing them, in some instances, to find their way into the inner housing sterilization chamber and interfere with the sterilization process therein.
It is accordingly an object of the present invention to provide an improved hot air impingement sterilizer of the type described in my co-pending U.S. application Ser. No. 044,909 in which the above-mentioned and other maintenance and access limitations and disadvantages are eliminated or minimized.